Fresno County Portable Traffic Control - Roadway Functionality
Subsystem Description
The Roadway Subsystem (RS) includes the equipment distributed on and along the roadway that monitors and controls traffic and monitors and manages the roadway itself. Equipment includes traffic detectors, environmental sensors, traffic signals, highway advisory radios, dynamic message signs, CCTV cameras and video image processing systems, grade crossing warning systems, and freeway ramp metering systems. HOV lane management, reversible lane management functions, and barrier systems that control access to transportation infrastructure such as roadways, bridges and tunnels are also supported. This subsystem also provides the capability for environmental monitoring including sensors that measure road conditions, surface weather, and vehicle emissions. In adverse conditions, automated systems can be used to apply anti-icing materials, disperse fog, etc. Work zone systems including work zone surveillance, traffic control, driver warning, and work crew safety systems are also included. To enhance security, safeguard systems such as blast shields, exhaust systems and other automated and remotely controlled systems to protect transportation infrastructure is also provided. In advanced implementations, this subsystem supports automated vehicle safety systems by safely controlling access to and egress from an Automated Highway System through monitoring of, and communications with, AHS vehicles. Intersection collision avoidance functions are provided by determining the probability of a collision in the intersection and sending appropriate warnings and/or control actions to the approaching vehicles.
Functional Area: Field Management Stations Operation
Supports direct communications between field management stations and the local field equipment under their control.
Functional Area: Roadway Basic Surveillance
Field elements that monitor traffic conditions using loop detectors and CCTV cameras.
Functional Area: Roadway Equipment Coordination
Field elements that control and send data to other field elements (such as environmental sensors that send data to a DMS or coordination between traffic controllers on adjacent intersections), without center control.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall include sensors that provide data and status information to other field element devices, without center control. | Existing |
Functional Area: Roadway Signal Controls
Field elements including traffic signal controllers for use at signalized intersections; also supports pedestrian crossings.
| ID | Requirement | Status |
|---|---|---|
| 2 | The field element shall respond to pedestrian crossing requests by accommodating the pedestrian crossing. | Existing |
Functional Area: Roadway Work Zone Traffic Control
Field elements in maintenance and construction areas including CCTV cameras, driver information systems (such as DMS), and gates/barriers that monitor and control traffic and provide information directly to drivers in affected areas.
| ID | Requirement | Status |
|---|---|---|
| 3 | Under the control of field personnel within maintenance vehicles, the field element shall include driver information systems (such as dynamic messages signs and highway advisory radios) that advise drivers of activity around a work zone through which they are currently passing. | Existing |
| 4 | The field element shall control access to the work zone using automated gate or barrier systems. This includes automated flagger assistance devices that include automated gate arms and other automated gate/barrier systems. | Existing |